1. Field of the Invention
The present invention relates to a liquid supply system for supplying a tank mounted on a carriage, executing a reciprocating motion and supporting a recording head and the tank, with ink from a replenishing tank different from the tank on the carriage when the carriage moves to a predetermined position, and a liquid discharge recording apparatus provided with such liquid supply system.
2. Related Background Art
A conventional liquid discharge recording apparatus is disclosed in the Japanese Patent Application Laid-open Nos. 9-234881 and 10-29318. In the liquid discharge recording apparatus disclosed therein is provided, on a reciprocably supported carriage, with a tank unit containing ink constituting recording liquid and a recording head for discharging the ink, supplied from such tank unit, toward a recording medium such as a recording sheet. The recording sheet is conveyed by conveying means, and the carriage executes a reciprocating motion along a line in the transversal direction of the recording sheet, perpendicular to the conveying direction. The recording head on the carriage discharges the ink toward the recording sheet in the course of the reciprocating motion of the carriage, thereby recording an image on the recording sheet. The tank unit on the carriage contains an absorbent member for holding ink by absorbing ink therein. Such absorbent member can be composed, for example, of a porous member such as sponge or a fibrous body.
The liquid discharge recording apparatus described in the aforementioned patent applications is provided with a replenishing tank different from the tank supported on the carriage. The replenishing tank contains ink for replenishment to the tank unit on the carriage. The replenishing tank is fixed for example to the housing of the liquid discharge recording apparatus, in the vicinity of the moving range of the carriage. To the replenishing tank, there is connected an end of a tubular liquid supply path for supplying the tank unit on the carriage with the ink contained in such replenishing tank. In the ink replenishment to the tank unit on the carriage, the carriage is moved to a predetermined position or a replenishing position to the tank unit, and the ink in the replenishing tank is supplied through the liquid supply path to the tank unit on the carriage stopped at such replenishing position. In such liquid discharge recording apparatus of so-called pit-in system, the ink is replenished from the replenishing tank to the tank unit before all the ink therein is consumed in the recording operation.
In the recording apparatus of the above-described pit-in system, it is being required to reduce the ink supply time from the replenishing tank to the ink tank and to rapidly move the carriage from the predetermined replenishing position to the recording area, in order to improve the throughput.
However, in the above-described conventional liquid discharge recording apparatus, a shortened ink supply time may result in a defective printing or ink leakage from the ink tank since the absorbent member is incapable of rapidly absorbing the replenished ink.
Also in such liquid discharge recording apparatus, in the liquid supply path for supplying the ink from the replenishing tank, fixed for example on the housing, to the tank unit on the carriage, the ink may drip off from the end portion of the liquid supply path for example by a vibration generated in the movement of the carriage, thus resulting in ink leakage. Also in case the ink supply path is so constructed that the end portion of the supply tube extending from the replenishing tank extends downwards parallel to the direction of gravity, so as to form a meniscus at the end portion of the supply tube in the interval of the replenishing operations, such meniscus has to be maintained in stable manner throughout the interval of the replenishing operations in order that the ink replenishing operation can be stably and securely executed. If the meniscus is formed unstably in such ink supply path, the meniscus may be easily broken for example by a vibration, thus leading to ink leakage.
In consideration of the foregoing, an object of the present invention is to provide, for use in a liquid discharge recording apparatus provided with a carriage supporting a tank unit containing an absorbent member and a recording head and adapted to replenish ink from a replenishing tank to the tank unit on the carriage when the carriage moves to a predetermined position, a liquid supply system enabling rapid absorption of the ink in the absorbent member thereby allowing prompt ink replenishment, a liquid discharge recording apparatus provided with such liquid supply system, and a liquid container adapted for use as the tank unit to be supported on the carriage.
Another object of the present invention is to provide, for use in the above-mentioned liquid discharge recording apparatus, a liquid supply system ensuring highly reliable ink supply without ink leakage in the ink supply path from the replenishing tank to the tank unit on the carriage, and a liquid discharge recording apparatus provided with such liquid supply system.
The above-mentioned objects can be attained, according to the present invention, by a liquid container containing therein an absorbent member for temporarily supporting, by a capillary force, liquid to be supplied to a recording head for discharging liquid and mounted together with the recording head on a linearly reciprocating carriage and subjected to liquid replenishment to the absorbent member when the carriage is moved to a predetermined position, wherein the surface of the absorbent member is applied with a polymer including a second portion having a lyophilic radical for providing the surface with lyophilicity and also including a first portion having a radical of an interfacial energy different from that of the aforementioned lyophilic radical and approximately equal to the surface energy of the aforementioned surface, and the first portion is oriented toward the surface while the second portion is oriented in a direction different from the surface.
According to the present invention, there is also provided a liquid supply system comprising a tank unit containing therein an absorbent member for temporarily supporting, by a capillary force, liquid to be supplied to a recording head for discharging liquid and mounted together with the aforementioned recording head on a linearly reciprocating carriage, and a replenishing tank containing liquid to be replenished to the tank unit when the carriage is moved to a predetermined position, wherein the surface of the absorbent member is applied with a polymer including a second portion having a lyophilic radical for providing the surface with lyophilicity and also including a first portion having a radical of an interfacial energy different from that of the aforementioned lyophilic radical and approximately equal to the surfacial energy of the aforementioned surface, and the first portion is oriented toward the surface while the second portion is oriented in a direction different from the surface.
According to the present invention, there is further provided a liquid supply system comprising a tank unit containing liquid to be supplied to a recording head for discharging liquid and mounted together with the aforementioned recording head on a linearly reciprocating carriage, a replenishing tank containing liquid to be replenished to the tank unit when the carriage is moved to a predetermined position, and a tubular liquid supply path of which an end is connected to the replenishing tank for supplying the tank unit with the liquid contained in the replenishing tank while the other end is positioned above the tank unit when the carriage is moved to the aforementioned predetermined position, wherein the internal surface of the liquid supply path is applied with a polymer including a second portion having a lyophilic radical for providing the internal surface with lyophilicity and also including a first portion having a radical of an interfacial energy different from that of the aforementioned lyophilic radical and approximately equal to the surfacial energy of the aforementioned internal surface, and the first portion is oriented toward the internal surface while the second portion is oriented in a direction different from the surface.
According to the present invention, there is further provided a liquid supply system comprising a tank unit containing therein an absorbent member for temporarily supporting, by a capillary force, liquid to be supplied to a recording head for discharging liquid and mounted together with the aforementioned recording head on a linearly reciprocating carriage, a replenishing tank containing liquid to be replenished to the tank unit when the carriage is moved to a predetermined position, and a tubular liquid supply path of which an end is connected to the replenishing tank for supplying the tank unit with the liquid contained in the replenishing tank while the other end is positioned above the tank unit when the carriage is moved to the aforementioned predetermined position, wherein the surface of the absorbent member and the internal surface of the liquid supply path are rendered lyophilic and each of such lyophilicized surfaces is applied with a polymer including a second portion having a lyophilic radical for providing the surface with lyophilicity and also including a first portion having a radical of an interfacial energy different from that of the aforementioned lyophilic radical and approximately equal to the surfacial energy of the aforementioned internal surface, and the first portion is oriented toward the internal surface while the second portion is oriented in a direction different from the surface.
According to the present invention, there is further provided a liquid discharge recording apparatus comprising a carriage supporting a tank unit containing therein an absorbent member for temporarily supporting liquid by a capillary force and a recording head for executing a recording operation by discharging the liquid supplied from the tank unit toward a recording medium, and adapted to reciprocate along a line parallel to the recording medium, and a replenishing tank containing liquid to be replenished to the tank unit when the carriage is moved to a predetermined position, wherein the surface of the absorbent member is applied with a polymer including a second portion having a lyophilic radical for providing the surface with lyophilicity and also including a first portion having a radical of an interfacial energy different from that of the aforementioned lyophilic radical and approximately equal to the surfacial energy of the aforementioned surface, and the first portion is oriented toward the internal surface while the second portion is oriented in a direction different from the surface.
Preferably the aforementioned liquid discharge recording apparatus further comprises a tubular liquid supply path of which an end is connected to the replenishing tank for supplying the tank unit with the liquid contained in the replenishing tank while the other end is positioned above the tank unit when the carriage is moved to the aforementioned predetermined position, wherein the internal surface of the liquid supply path is applied with a polymer including a second portion having a lyophilic radical for providing the internal surface with lyophilicity and also including a first portion having a radical of an interfacial energy different from that of the aforementioned lyophilic radical and approximately equal to the surfacial energy of the aforementioned internal surface, and the first portion is oriented toward the internal surface while the second portion is oriented in a direction different from the surface.
Furthermore, in the aforementioned liquid discharge recording apparatus, the replenishing tank may be provided in plural units with different kinds of liquids contained therein, and the tank unit may be provided in plural units respectively corresponding to the kinds of the replenishing tanks.
In the foregoing inventions, it is preferred that the absorbent member is composed of a fibrous body having olefinic resin at least on the surface thereof and the polymer is composed of polyalkyl siloxane provided with a lyophilic radical.
It is further preferred that the internal surface, provided with the polymer, of the aforementioned liquid supply path is composed of an olefinic resin and the polymer is composed of polyalkyl siloxane provided with a lyophilic radical.
According to the present invention described in the foregoing, the surface of the absorbent member, contained in the liquid container supported as the tank unit on the carriage, there is provided a polymer including a second portion having a lyophilic radical and a first portion having a radical of an interfacial energy different from that of the aforementioned lyophilic radical and approximately equal to the surfacial energy of the aforementioned surface, and the first portion is oriented toward the aforementioned surface while the second portion is oriented in a direction different from the surface, whereby the surface of the absorbent member is rendered lyophilic. In such configuration, when the liquid is replenished from the replenishing tank to the absorbent member in the liquid container when the carriage supporting the recording head together with the liquid container is moved to the predetermined position, the replenished liquid promptly absorbed in the absorbent member because the surface thereof is lyophilized, whereby the liquid replenishing operation into the liquid container can be completed within a short time. In a liquid supply system or a liquid discharge recording apparatus in which such liquid container is mounted as the tank unit together with the recording head on the carriage, when the liquid is replenished to the absorbent member in the tank unit in case the liquid therein decreases by the liquid discharging operation of the recording head, the liquid penetrating in the absorbent member reaches the gas-liquid interface therein within a short time. Thus the liquid present in the absorbent member prior to the replenishment becomes connected with the replenished liquid. In comparison with a case where the surface of the absorbent member is not rendered hydrophilic, there is significantly reduced the time required for the tank unit to reach a usable state after replenishment. It is therefore possible to achieve the liquid replenishment to the tank unit within a short time and to reduce the time from the start of the liquid replenishing operation to the sufficient filling of the usable liquid in the tank unit. In this manner, the lyophilizing treatment of the absorbent member in the tank unit enables prompr and secure liquid replenishment into the absorbent member. Consequently there can be realized a highly reliable liquid discharge recording apparatus of pit-in system in which the liquid replenishment to the tank unit mounted on the carriage is executed in a predetermined position.
Also in a liquid supply system or a liquid discharge recording apparatus in which the above-described liquid container is mounted as the tank unit on the carriage and the liquid in the replenishing tank is replenished to the tank unit through a tubular liquid supply path when the carriage is moved to a predetermined position, the lyophilized internal surface of the liquid supply path allows to form a stable meniscus at the end portion of the liquid supply path during the interval of the liquid replenishing operations. Thus, even in case a vibration is generated in the recording apparatus for example by the carriage movement or an impact is applied to the recording apparatus, the meniscus is stably supported at the end portion of the liquid supply path and is not easily broken. Therefore, the liquid leakage from the end portion of the liquid supply path in the interval of the liquid replenishing operations to the tank unit on the carriage, and there can be secured highly reliable liquid replenishment to the tank unit.